<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>相对定位</title>
	<style type="text/css">
		*{
			margin: 0px;
			padding: 0px;
		}
		li{
			list-style: none;
			width: 200px;
			height: 200px;
			background: red url() 0 0 no-repeat;
			float: left;
			
		}
		.box2{
			background: blue;
			position: relative;
			top: 0px;
			left: 0px;
		}
		.box3{
			background: yellow;
		}
		.box4{
			background: green;
		}

	</style>
</head>
<body>
	<ul>
		<li class="box1">box1</li>
		<li class="box2">box2</li>
		<li class="box3">box3</li>
		<li class="box4">box4</li>
	</ul>
</body>
</html>